Evaluation of the nutritional value of ryegrass-white clover leaf protein concentrate

摘要

The effects of offering chickens a diet containing ryegrass (Lolium perenneL.)-white clover (Trifolium repensL.) leaf protein concentrate (LPC) as the main protein source were compared to those of offering a diet containing heat-treated soybean meal (SBM) as the main protein source. The LPC diet had a lower nutritional value than the SBM diet used in the growth trial. The addition of methionine or cystine to the LPC diet improved both the food utilisation and weight gain of chickens given this diet to equivalent levels to those of chickens offered the SBM diet. Chickens given the LPC diet developed pancreatic hypertrophy, had increased levels of pancreatic enzyme activity (trypsin and chymotrypsin), and lower mean ileal amino acid (26) and cystine digestibility (45) estimates compared to those of chickens given the SBM diet. These physiological and metabolic effects are characteristic of chickens given raw SBM or trypsin inhibitors. It was, therefore, concluded that methionine and/or cystine must be added to diets containing LPC because of the probable presence of trypsin inhibitors in LPC.